       (transact! conn [[:db/add -1 :friend 296]])
   
       ; create an entity and set multiple attributes (in a single transaction
-      ; equal tempids will be replaced with the same unused yet entid)
+      ; equal tempids will be replaced with the same yet unused entid)
       (transact! conn [[:db/add -1 :name \"Ivan\"]
                        [:db/add -1 :likes \"fries\"]
                        [:db/add -1 :likes \"pizza\"]

                        :name   \"Oleg\"
                        :likes  [\"fish\"]}])

      ; ref attributes can be specified as nested map, that will create netsed entity as well
      (transact! conn [{:db/id  -1
                        :name   \"Oleg\"
                        :friend {:db/id -2

                       {:db/id 296, :friend -1}])
      ; equivalent to
      (transact! conn [[:db/add  -1 :name   \"Oleg\"]
                       [:db/add 296 :friend -1]])"
  ([conn tx-data] (transact! conn tx-data nil))
  ([conn tx-data tx-meta]
    {:pre [(conn? conn)]}
